Thank you for your message.
Great product. Been using this for about 2 months now and it's great.
Thank you very much. :)
I am looking for a way (remotely if possible) to check if I registered a host.
a. What key did I use?
You can check it in the License information column, if you switch your View mode from Thumbnails to Details. (Right-click anywhere in the connections region of the Viewer window -> Details). You should be loggen on that Host.
I am also wondering what the symptoms of not registering a host would be.
If you try to connect to unregistered Host, you'll see a window which will ask you to register that Host.
Do I have to register a viewer?
No. Viewer only stores keys in the License key storage.
Lastly, what would happen if I registered the same host 2x?
Host will be re-registered. Last license key applied will be active.